She might not have any films to promote - if you disclude her cameo in Sofia Coppola's The Bling Ring - but Paris Hilton is certainly making the most of the party circuit in this years' Cannes festival.

The 31-year-old Simple Life star was out again on Saturday night with her hunky 21-year-old boyfriend River Viiperi keeping close by.

And the Spantour of the French film festival with a number of stop offs at various high-profile events.

The drinks have been flowing as the pair have partied late into the night since they arrived at the annual event.ish model took a moment to celebrate his one-year anniversary to the hotel heiress - and sparked engagement rumours as he referenced her as his 'future wife'.

Wedding bells? Paris Hilton and River Viiperi continue to party in Cannes as they celebrate their one-year anniversary together and River hints at marriage

The very happy couple have been inseparable during their

They were in the company of legendary film director and Monty Python Terry Gilliam who was hosting the Zero Theorem party at Torch nightclub at Vegaluna Beach.

Blonde ambition: The Hilton hotel heiress looked well groomed for her latest night out in Cannes

The director's latest film stars Tilda Swinton and Matt Damon in a typically wacky adventure.

For the night's celebrations Paris wore an off-the-shoulder black sparkling catsuit, high heels, a classic white watch, and Avakian jewellery.

Meanwhile dapper River looked sharp in a finely tailored suit for their new night of partying.

Midnight style: Paris stepped out in a stunning off-the-shoulder black catsuit for her latest night out

Relaxing on a staircase together the couple looked blissfully happy.

And it was on social network site Instagram that the model made reference to making the blonde bombshell his permanent squeeze.

'Happy 1 year anniversary to the gorgeous, beautiful, perfect, most amazing & most caring girl in this Planet,' he said, lavishing praise on the Californian beauty.

Telling tweets? River tweeted an Instagram link to a picture of himself with Paris where he called her his 'future wife'

The couple were originally thought to have got together last September during New York Fashion week, however it would seem their couple status had been running since the time of Cannes last year as they now celebrate one year together.

And River's statement that Paris is his 'future wife' has already sparked rumours that they may one day tie-the-knot.